As is well-known, a wrench is a hand tool used for holding and turning elements such as nuts, pipes, spark plugs and the like. There are many kinds of wrenches, including monkey wrenches, single-ended wrenches, double-ended wrenches, box wrenches and the like. Two common wrenches are the socket wrench, which combines an offset handle with a male drive piece having a spring-loaded bearing lock on various sized sockets, and a ratchet wrench, which is a socket wrench having a ratchet mechanism which controls the direction of applied torque.
Wrenches are used by mechanics in all sorts of applications, and under all sorts of conditions. For example, an automobile mechanic may be required to apply a ratchet wrench to various elements in an automobile engine. However, if such elements are in difficult-to-reach locations, proper application of torque can be difficult. This problem is especially apparent if the ratchet wrench is not long enough to properly reach the desired element.
It is known to provide an extendible handle for ratchet wrenches and similar tools having an elongated shank, in order to permit the operator to increase the amount of torque exerted during the use of the tool. Various devices and configurations have been disclosed providing for extensible handles. Each of these extensible handles have various locking mechanisms. Most of the locking mechanisms are complex in the number of parts required to achieve the locking and unlocking capability. In addition, most of the locking mechanisms are inherently expensive to manufacture and/or assemble. Because of the complex mechanisms previously used for performing the locking and unlocking function, the devices have been subject to increased rates of failure. Therefore, the prior known telescopic wrench devices have been undesirable, and commercially unsuccessful, because of the high cost of manufacturing and assembly, and the high rate of failure of these locking mechanisms.
Therefore, it is desirable in the present invention to provide a simple locking mechanism for providing a telescopic element of a wrench or other hand tool. It is also desirable in the present invention to provide a locking mechanism which is simple to manufacture and assemble. Furthermore, it is desirable in the present invention to provide a locking mechanism which is reliable in operation.